Volatile and non-volatile memories in silicon with nano-crystal storage

Abstract

A single transistor memory structure, with changes in threshold voltage exceeding ≈ 0.25 V corresponding to single electron storage in individual nano-crystals, operating in the sub-3 V range, and exhibiting long term to non-volatile charge storage is reported. As a consequence of Coulombic effects, operation at 77 K shows a saturation in threshold voltage in a range of gate voltages with steps in the threshold voltage corresponding to single and multiple electron storage. The plateauing of threshold shift, operation at ultra-low power, low voltages, and single element implementation utilizing current sensing makes this an alternative memory at speeds lower than of DRAMs and higher than those of E2PROMs, but with potential for significantly higher density, lower power, and faster read.